NET JRF PART - A : Questions and Solutions : NET JUNE-2018

NET JRF PART - A : Questions and Solutions:

NET JUNE-2018

1.) In a sequence of 24 positive integers, the product of any two consecutive integer is 24 . If the 17th member of the sequence is 6 , the 7th member is 

(a) 24 (b) 4 (c) 6 (d) 17 

Ans. : (c) 6 .

Solution:

The only possible numbers of the sequence can be those integers which are divisors of 24 . Thus 1, 2, 3, 4, 6, 8, 12 and 24 can be members of the series. From the question the 17th member will be 6 hence 16th and 18th member will be 4 . Using the same reasoning we see that the sequence is

6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4,.....

Hence, we conclude that the 7th member of the series is 6 .